Laminated glass is safety glass which, even when broken by impact from the outside, shatters into few flying glass fragments. For this reason, laminated glass is widely used for applications such as cars, rail cars, aircrafts, boats and ships, and buildings. Laminated glass is produced by sandwiching an interlayer film for laminated glass between a pair of glass plates. Such laminated glass used for openings of vehicles or buildings are required to have high heat shielding properties.
Infrared rays having a wavelength of 780 nm or longer, which is longer than a wavelength of visible light, have a small amount of energy compared to ultraviolet rays. Infrared rays, however, have a large thermal effect, and are emitted as heat when absorbed by a substance. For this reason, infrared rays are commonly referred to as heat rays. Therefore, infrared rays are required to be sufficiently shielded in order to give a laminated glass having better heat shielding properties.
The below-mentioned Patent Document 1 discloses an interlayer film containing a tin-doped indium oxide particle (a ITO particle) or an antimony-doped tin oxide particle (an ATO particle) as an interlayer film that effectively blocks infrared rays (heat rays). The below-mentioned Patent Document 2 discloses an interlayer film containing a tungsten oxide particle.